Microsoft Excel can present two series of data points together on the horizontal axis, but if the number scale for each series dramatically differs, the data will not be readable. Using a two ...

However, it does show the usefulness of dual y-axes in a real world test. If you put these charts side-by-side, it would be hard to see if they match up. If you charted them on a single axis ...

Chaffetz’s chart falls into a category known as a dual-axis chart. On the left side, cancer screenings and prevention services are plotted in the millions. On the right side, abortions are ...